Electric switch device having constant contact pressure



E. P. LARSH 3,

ELECTRIC SWITCH DEVICE HAV ING CONSTANT CONTACT PRESSURE Dec. 20, 1965 Filed Oct. 9, 1964 IN VENTOR.

EVERETT P. LARSH ATTORNEY United States Patent 3,293,398 ELECTRIC SWITCH DEVICE HAVING CONSTANT CONTACT PRESSURE Everett P. Larsh, 124 E. Monument Ave., Dayton, Ohio 45402 Filed Oct. 9, 1964, Ser. No. 402,758 7 Claims. (Cl. 200-165) This invention relates to electric switch device.

It is an object of this invention to provide electric switch apparatus in which there is substantially constant pressure between a movable contact member and a stationary contact member when the switch is in an'actuated position, even though the position of a switch actuator member may vary.

Another object of this invention is to provide such switch apparatus which can be produced at relatively low costs and which is long-lived.

Other objects and advantages resides in the construction of parts, the combination thereof, the method of manufacture, and the mode of operation, as will become more apparent from the following description.

In the drawing:

FIGURE 1 is a perspective view, partially exploded, showing electric switch apparatus of this invention in a stage of assembly thereof.

FIGURE 2 is a perspective view, similar to FIGURE 1, showing another stage in assembly of the switch apparatus of this invention.

FIGURE 3 is a perspective view similar to FIGURES 1 and 2 showing switch apparatus of this invention.

FIGURE 4 is an enlarged section view taken substantially on line 44 of FIGURE 3. FIGURE 4 also shows a portion of an actuator element which may be used for operation of the switch apparatus.

FIGURE 5 is a section view, similar to FIGURE 4, showing the actuator element in engagement with a portion of the switch apparatus.

FIGURE 6 is an enlarged fragmentary section view showing a portion of the switch apparatus and the actuator element in normal operation.

Referring to the drawing in detail, electric switch app-aratus of this invention comprises a base 10. Preferably, the base 10 is composed of any suitable insulator material. A stationary contact member 12 of electrically conductive material and having a terminal post 14 is carried by the base 10. A conductor lead 16 is shown attached to the terminal post 14.

Adjacent the stationary contact member 12 is an abutment member 18 which is attached to the base 10 integrally or in any other suitable manner.

A resilient stem or strip 20 of conductor material is attached to the base 10 at a position spaced from the stationary contact member 12. A conductor lead 21 is shown connected to the stem 20. The resilient stem or strip 20 extends in a cantilever manner to a position adjacent the stationary contact member 12. The stem 20 is shown as having a bent end portion 22 which carries a contact member 24 which is secured thereto in any suitable manner. Thus, the contact member 24 is movable with movement of the bent end portion 22 of the stem 20. The bent end portion 22 is normally held firmly against the abutment member 18 by the resiliency of the stem 20. Thus, the abutment member 18 limits the normal spacing between the stationary contact member 12 and the contact member 24.

A tab or abutment member 26 is carried by the bent end portion 22 of the stem 20 for a purpose discussed below.

FIGURE 1 shows a resilient leaf or arm 30 before attachment thereof to the stem 20. Preferably, the leaf "ice or arm 30 is bent in the general form of a letter V or a letter U and has a connection portion 32 secured to the stem 20 in any suitable manner, such as by soldering or welding or the like. However, it is to be understood that the leaf or arm 30 may be integral with the stem 20, if desired.

Following attachment of the resilient leaf or arm 30 to the stem 20, the assembly may appear as shown in FIG- URE 2 in which an extension portion 34 of the resilient arm 30 extends angularly from the stem 20. Then, the extension portion 34 of the arm 30 is forced toward the stem 20 and, with slight lateral movement, the end of the arm 30 is positioned under the tab 26. The force applied to the etxension portion 34 to move the extension portion 34 from the position thereof shown in FIGURE 2 to the position thereof shown in FIGURE 3 is against the resilient forces of the arm 30 which tend to maintain the extension portion 34 in the position thereof shown in FIG- URE 3. Thus, the extension portion 34 of the arm 30 is in resilient engagement with the tab 26. Thus, the extension portion 34 of the arm 30 is in a resiliently bent condition between the main portion of the stem 20 and the tab 26, as shown in FIGURE 4. p The extension portion 34 of the arm 30 has a contact portion or contact member 38. The contact member 38 is adapted to be engaged by any suitable actuator member 40 for actuation of the switch apparatus. As the actuator member 40 engages the contact portion 38, the arm 30 and the stem 20 are moved together so that the stem 20 is resiliently bent and the contact member 24 is moved into engagement with the stationary contact member 12, as shown in FIGURE 5. Thus an electric circuit is created between the conductor lead 16 and the conductor lead 21,. Then additional movement of the actuator member 40 toward the stem 20 causes additional bending action of the arm 30 as the extension portion 34 of the arm 30 moves from engagement with the tab 26. Thus, the arm 30 is bent to the position thereof shown in FIGURE 6 and assures firm pressure of the contact member 24 against the stationary cont-act member 12.

In the operation of many types of actuator members the position thereof when actuated does not remain constant. Frequently, vibration or other conditions cause an actuator member in its actuated position to move slightly.

As shown in FIGURE 6, slight changes in the actuated position of the actuator member 40 do not change the position of the contact member 24 with respect to the stationary contact member 12. As the actuated position of the actuator member 40 varies slightly, as shown in FIGURE 6, as a result of vibration or for other reasons, the bent position of the arm 30 changes while firm pressure of the contact member 24 against the stationary contact member 12 is maintained. Thus, the resilient arm 30 accommodates for possible overtravel of the actuator member 40 and also accommodates for other changes in the actuated position of the actuator member 40 while a substantially constant contact pressure between the contacts 24 and 12 is maintained.

When the actuator member 40 returns to the position thereof shown in FIGURE 4, the stem 20 and the extension portion 34 of the arm 30 immediately resiliently return to the positions thereof shown in FIGURE 4. Thus, the contact member 24 moves by snap action from engagement with the stationary contact member 12 when the actuator member 40 deactuates the switch apparatus. Thus, the electric circuit between the conductor lead 16 and the conductor lead 21 is opened.

Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts,

the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

The invention having thus been described, the following is claimed:

1. an electric switch device comprising: support structure, a stationary contact member carried by the support structure, an elongate resilient stem attached to the support structure at a fixed position in spaced relationship from the stationary contact member so that the stem extends from said fixed position to a position adjacent the stationary contact member, the resilient stem having an integral contact portion adjacent the stationary contact member, the stem being bendable to move the contact portion into engagement with the stationary contact member, abutment means fixedly carried by the support structure at a position spaced from the stationary contact member, the resiliency of the resilient stem urging the contact portion of the stem into engagement with the abutment means, the abutment means thus establishing the normal spacing between the contact por tion of the stem and the stationary contact member, an abutment member carried by the resilient stem adjacent the contact portion thereof,

a U-shaped resilient leaf member having an attachment leg connected to the resilient stem along a portion of the length thereof, the U-shaped resilient leaf member also having a free leg extending from the resilient stem, the free leg of the leaf member having an engagement portion intermediate the resilient stem and the abutment member carried thereby, said engagement portion of the free leg of the leaf member normally being in resilient engagement with the abutment member,

movement of the engagement portion of the free leg of the leaf member toward the resilient stem causing bending of the leaf member so that the attachment leg of the leaf member bends the stem toward the stationary contact member, thus causing movement of the contact portion of the stem into engagement with the stationary contact member, the engagement portion of the free leg of the resilient leaf member ordinarily being spaced from the abutment member during engagement of the contact portion of the stem with the stationary contact member.

2. Electric switch apparatus comprising:

stationary support structure,

a stationary contact member carried by the stationary support structure,

an elongate resilient stem supported by the stationary support structure at a position spaced from the stationary contact member, the stem having a contact portion fixedly secured thereto, the contact portion being adjacent the stationary contact memher, the contact portion being normally spaced from the stationary contact member, the resilient stem being bendable for engagement of the contact portion thereof with the stationary contact member,

an abutment element fixedly secured to the stem and carried thereby adjacent the contact portion and spaced therefrom,

a resilient arm attached to the resilient stem and having an engagement portion intermediate the abutment element and the contact portion, said engagement portion of the resilient arm normally engaging the abutment element, the force required to bend the resilient stem being less than the force required to bend the resilient arm,

means operably engageable with the resilient arm and movable toward the resilient stern for movement of the resilient arm away from the abutment element,

thus causing bending of the resilient stem so that the contact portion thereof engages the stationary contact member, said engagement portion of the resilient arm being movable toward and away from the abutment element while the contact portion remains in engagement with the stationary contact member as the resilient arm bends with respect to the resilient stem.

3. Electric switch apparatus comprising: stationary support structure having a first fixed support portion and a second fixed support portion,

a resilient stem carried by the stationary support structure at the first fixed support portion thereof, the resilient stem extending from the first fixed support portion to a position adjacent the second fixed support portion,

a constant element fixedly attached to the resilient stem adjacent the second support portion of the support structure,

stationary contact member carried by the support structure at the second support portion thereof,

the resilient stem having a normal position in which the contact element is spaced from the stationary contact member,

an abutment member fixedly attached to the resilient the resilient arm being operably movable toward'the resilient stern for bending the resilient stem so that the contact element engages the stationary contact member for flow of electrical current between the stationary contact member and the contact element, the resilient arm being further operably movable toward the resilient stem so that the engagement portion thereof becomes positioned intermediate the stem and the abutment member.

Electric switch apparatus comprising:

support structure provided with a first support position and a second support position, the support positions being in spaced-apart relationship,

abutment means carried by the support structure adjacent the first support position,

stationary contact member carried by the support structure at the first support position,

a resilient stem attached to the support structure at the second support position, the resilient stem extending from the second support position and having an engagement portion normally in engagement with the abutment member,

a contact element carried by the stem and normally spaced from the stationary contact member,

an abutment member carried by the stem and spaced therefrom,

a resilient arm attached to the resilient stem along the length thereof, the resilient arm extending from the resilient stem from a position adjacent the second support position, the resilient arm extending toward the contact element carried by the stem, the resilient arm having a bent portion adjacent the second support position, the resilient arm having an engagement portion engaging the abutment member carried by the stem, movement of the resilient arm toward the resilient stem initially causing bending of the stem so that the contact element engages the stationary contact member, further movement of the resilient arm toward the resilient stem causing bending of the resilient arm.

5. Electric switch apparatus comprising:

an elongate strip of resilient material, a portion of the strip adjacent one end thereof being a fixed portion, the strip being bendable from the fixed portion,

the strip having a contact portion fixedly secured thereto and spaced from the fixed portion,

a stationary contact member having a fixed position adjacent said contact portion of the strip,

the contact portion of the strip being engageable with the stationary contact member by bending action of the strip toward the stationary ontact, member,

the contact portion of the strip being normally out of engagement with the stationary contact member,

a resilient arm attached to the resilient strip at a position intermediate the fixed portion of the strip and the contact portion thereof, the resilient arm having a bent portion adjacent the fixed portion of the elongate strip, the resilient arm having an extension portion extending from the bent portion thereof in a general direction toward the contact portion of the strip,

an abutment member fixedly secured to the strip and extending therefrom at a position adjacent the contact portion thereof,

the extension portion of the resilient arm having an engagement part disposed intermediate the abutment member and the strip and normally in resilient engagement with the abutment member,

the resilient strip being operably bendable so that the contact portion thereof is moved toward the stationary contact member as pressure is applied to the resilient arm in a direction toward the resilient strip so that the contact portion engages the stationary con tact member while the extension portion of the resilient arm remains in engagement with the abutment member, increased pressure applied to the resilient arm in a direction toward the strip causing the extension portion of the resilient arm to move from en gagement with the abutment member and become positioned intermediate the abutment member and the strip, the extension portion of the resilient arm being movable to any position intermediate the abutment member and the strip while the contact portion of the strip remains in engagement with the station'- ary contact member.

6. Electric switch apparatus comprising:

support structure,

a stationary electrically conductive contact member carried by the support structure,

a resilient electrically conductive stem having a connection portion attached to the support structure at a position spaced from the stationary contact member, the resilient stern having an extension portion disposed adjacent the stationary contact member, the extension portion having an electrically conductive contact portion which is normally spaced from the stationary contact member but which is engageable therewith by bending action of the resilient stem,

the extension portion of the resilient stem having an abutment portion spaced from the contact portion,

a generally U-shaped resilient leaf, the U-shaped resilient leaf having a pair of leg portions, there being a first leg portion and a second leg portion, the first leg portion being attached to the resilient stem along part of the length thereof intermediate the contact portion and the connection portion thereof, the second leg portion of the resilient leaf extending in a direction from the connection portion of the stem toward the contact portion thereof, the second leg portion of the resilient leaf being bent toward the stem and having a part resiliently disposed intermediate the stem and the abutment portion of the extension portion of the stem,

pressure applied to the second leg portion of the leaf in a direction toward the stem causing increased bending of the second leg portion of the U-shaped leaf toward the stem and thus causing a movement of the stem toward the stationary contact member and causing engagement of the contact portion with the stationary contact member, additional pressure applied to the second leg port-ion of the leaf in a direction toward the stem causing increased bending movement of the second leg portion of the leaf toward the stem as the contact portion remains in engagement with the stationary contact member.

7. Electric switch apparatus comprising:

stationary support structure,

a stationary contact member carried by the stationary support structure,

a resilient stern having a connection portion attached to the stationary support structure, the resilient stern having a fixed contact portion fixedly attached thereto adjacent the stationary contact member, the resilient stem having a body portion intermediate the connection portion and the contact portion,

the resilient stem being bendable toward the stationary contact member to cause engagement of the fixed contact portion thereof with the stationary contact member,

the resilient stern having a resilient arm portion extending from the body portion thereof in a general direction toward the contact portion of the resilient stem,

the stem having an abutment portion fixedly attached thereto adjacent the fixed contact portion thereof,

the resilient arm portion being bent toward the body portion, the resilient arm portion having an abutment portion normally engaging the abutment portion of the stem and maintaining the resilient arm portion in a bent condition and limiting the extending position of the arm portion with respect to the body portion of the stern,

engagement means engageable with the resilient arm portion of the stem at a portion thereof spaced from the stationary support structure for movement of the resilient arm portion toward the body portion of the stem while the resilient arm portion remains in engagement with the abutment portion thus causing bending action of the stern toward the stationary contact member for engagement of the contact portion of the stem with the stationary contact member, the arm portion of the stem being further bendable to ward the body portion of the stem and away from engagement with the abutment portion while there is engagement between the contact portion of the stem and the stationary contact member.

References Cited by the Examiner UNITED STATES PATENTS 1,499,370 I 7/1924 James 200-l59 2,270,727 1/1942 Evans 200 2,402,173 6/1946 Malone 200165 ROBERT K. SCHAEFER, Primary Examiner. H. HOHAUSER, Assistant Examiner. 

1. AN ELECTRIC SWITCH DEVICE COMPRISING: SUPPORT STRUCTURE, A STATIONARY CONTACT MEMBER CARRIED BY THE SUPPORT STRUCTURE, AN ELONGATE RESILIENT STEM ATTACHED TO THE SUPPORT STRUCTURE AT A FIXED POSITION IN SPACED RELATIONSHIP FROM THE STATIONARY CONTACT MEMBER SO THAT THE STEM EXTENDS FROM SAID FIXED POSITION TO A POSITION ADJACENT THE STATIONARY CONTACT MEMBER, THE RESILIENT STEM HAVING AN INTEGRAL CONTACT PORTION ADJACENT THE STATIONARY CONTACT MEMBER, THE STEM BEING BENDABLE TO MOVE THE CONTACT PORTION INTO ENGAGEMENT WITH THE STATIONARY CONTACT MEMBER, ABUTMENT MEANS FIXEDLY CARRIED BY THE SUPPORT STRUCTURE AT A POSITION SPACED FROM THE STATIONARY CONTACT MEMBER, THE RESILIENCY OF THE RESILIENT STEM URGING THE CONTACT PORTION OF THE STEM INTO ENGAGEMENT WITH THE ABUTMENT MEANS, THE ABUTMENT MEANS THUS ESTABLISHING THE NORMAL SPACING BETWEEN THE CONTACT PORTION OF THE STEM AND THE STATIONARY CONTACT MEMBER, AN ABUTMENT MEMBER CARRIED BY THE RESILIENT STEM ADJACENT THE CONTACT PORTION THEREOF, A U-SHAPED RESILIENT LEAF MEMBER HAVING AN ATTACHMENT LEG CONNECTED TO THE RESILIENT STEM ALONG A PORTION OF THE LENGTH THEREOF, THE U-SHAPED RESILIENT LEAF MEMBER ALSO HAVING A FREE LEG EXTENDING FROM THE RESILIENT STEM, THE FREE LEG OF THE LEAF MEMBER HAVING AN ENGAGMENT PORTION INTERMEDIATE THE RESILIENT STEM AND THE ABUTMENT MEMBER CARRIED THEREBY, SAID ENGAGEMENT PORTION OF THE FREE LEG OF THE LEAF MEMBER NORMALLY BEING IN RESILIENT ENGAGEMENT WITH THE ABUTMENT MEMBER, MOVEMENT OF THE ENGAGMENT PORTION OF THE FREE LEG OF THE LEAF MEMBER TOWARD THE RESILIENT STEM CAUSING BENDING OF THE LEAF MEMBER SO THAT THE ATTACHMENT LEG OF THE LEAF MEMBER BENDS THE STEM TOWARD THE STATIONARY CONTACT MEMBER, THUS CAUSING MOVEMENT OF THE CONTACT PORTION OF THE STEM INTO ENGAGEMENT WITH THE STATIONARY CONTACT MEMBER, THE ENGAGEMENT PORTION OF THE FREE LEG OF THE RESILIENT LEAF MEMBER ORDINARILY BEING SPACED FROM THE ABUTMENT MEMBER DURING ENGAGEMENT OF THE CONTACT PORTION OF THE STEM WITH THE STATIONARY CONTACT MEMBER. 